The stretching separation and coalescence are only considered in the O’Rourke model while the bounce, reflexive separation and the secondary breakup under high Weber collision are ignored. Furthermore, the influences of droplet property and collision condition on the collision regimes are not included in the O’Rourke model so that the predicted critical Weber numbers are underestimated. In the composite collision model, the collision regimes were revised to consider the influence of droplet viscosity and environmental pressure, and the bounce, coalescence, reflexive separation, stretching separation and the secondary breakup under high Weber collision were also considered. Moreover, the influences of droplet viscosity and environmental pressure on the spray collision were investigated based on the composite collision model. The results showed that the probability of bounce was increased due to the increasing of environmental pressure while the probability of coalescence was decreased. However, the probability of coalescence was increased with the increasing of droplet viscosity while the probability of collision separation was reduced.